A Washington Post survey of economists over the weekend found that 90 percent think it’s a terrible idea for Trump to curb immigration to the U.S. Experts overwhelmingly predict it would slow growth — the exact opposite of what Trump wants to do with MAGAnomics.

"Restricting immigration will only condemn us to chronically low rates of economic growth. It also increases the risk of the recession," said Bernard Baumohl, chief global economist at The Economic Outlook Group.

Thomas Simmons, chief economist at investment firm Jefferies, called the idea "absolutely harmful to an economy with a population undergoing the demographic transformation."

The bottom line is: America needs more workers. Growth happens when one of two things occurs: The economy gets more workers or the existing workers become more productive. At the moment, both of those factors are red flags. Productivity growth is sluggish and, as Trump himself has pointed out many times, the percent of American adults who actually work — the labor force participation rate — is hovering at the lowest levels since the 1970s.

A big part of the problem is the Baby Boomers are starting to retire. The United States needs more people to replace them, but the U.S. birth rate just hit an historic low, according to the Centers for Disease Control and Prevention. That’s why most economists, demographers and business owners keep calling for more immigration, not less.

"Limiting immigration to the U.S. is a grave mistake," says Mark Zandi, chief economist of Moody’s Analytics. "The only way to meaningfully increase U.S. economic growth on a sustained basis anytime soon is to increase immigration."

During the campaign, Zandi predicted that Trump’s protectionist stances on trade and immigration would lead to a "lengthy recession." According to Zandi’s economic models, Trump’s worst policy was his plan to deport 11 million illegal immigrants currently in the country.

Now scaling back on legal immigration is a serious part of the policy discussion.

Congress and the White House are dealing with a slew of issues. Immigration appeared to be sidelined until a much-cited Politico report last week that top Trump aides are actively working with Republican Senators Tom Cotton of Arkansas and David Perdue of Georgia to cut legal immigration by as much as 50 percent. It would be a revised version of the RAISE Act that the senators introduced in February, which would cut back on the number of refugees allowed in each year and make it much harder for anyone other than spouses or minor children of U.S. citizens or permanent residents to immigrate.

Trump still sees action on immigration as a critical part of his agenda. He brought up on his trip to France last week.

"What I’d like to do is a comprehensive immigration plan," the president told reporters on his way to Paris. "But our country and political forces are not ready yet."

If Trump can’t get the bigger immigration reform he wants, he’s likely to push for something like the RAISE Act. Trump believes America needs to limit immigration, both legal and illegal, to give workers at home a better chance. One of the proposals Senators Cotton and Perdue are thinking about is slashing the number of legally-issued green cards from 1 million a year to 500,000 over the next decade.

Trump portrays immigrants as scooping up American jobs. But the data appear to tell a different story.

U.S. unemployment is 4.4 percent. In May, unemployment hit the lowest level since 2001, a milestone Trump celebrated. That implies there aren’t many people struggling to find work. At the same time, the U.S. has 5.7 million job openings, which is near a record high. It’s been that way for a year now. Business leaders of big and small firms complain they can’t find enough workers. They are especially vocal about not being able to find enough people for really low-skilled, low-pay work and for really highly skilled jobs.

Take Bayard Winthrop. He is founder and CEO of American Giant, a company that Slate said produces the "greatest hoodie ever made." American Giant makes those masterpiece sweatshirts by using only U.S. workers, U.S. cotton and U.S. manufacturing. In other words, Winthrop is the living embodiment of the "Made in America" a movement Trump is trying to resurrect. Yet one of the biggest problems Winthrop faces is not enough American workers want to do the hard work of picking cotton.

"If you go through our supply chain and talk to a lot of the business that are ginning cotton, dyeing and finishing cotton, what you hear pretty universally is they have open job requests but few people actually want these entry-level, lower wage jobs,” he said Monday in an interview with WAMU radio. His message to Trump is: "Make immigration much more accessible."

Trump is already heeding the calls for more lower-skilled workers. His administration just bumped up visas for seasonal foreign workers by 15,000, a 45 percent increase from last year.

There’s little love among economists and business leaders for a 50 percent cut in immigration overall, but there is growing support for moving the U.S. to a more merit-based immigration system. The idea is to attract more of the immigrant workers that the U.S. desperately needs. At the moment, only 15 percent of green cards are issued for employment reasons, according to the Department of Homeland Security data.

"There is a case for adopting a Canada-style system of ‘points’ whereby preference is given to people with desired skills," says Martin Barnes, chief economist at BCA Research in British Columbia, Canada.

The vast majority of legal immigrants are entering the country because they are relatives of someone already in the U.S. It’s known as "chain immigration," and the RAISE Act wants to limit that substantially so only spouses and children could come with a visa holder, not more extended relatives.

Immigrants also tend to start more businesses. While startup founders in Silicon Valley are glorified, the reality is, new business formation in the U.S. is near a 40-year low. That worries Carl Tannebaum, chief economist at Northern Trust, greatly.

"Countries that get collectively older are granted fewer patents, start fewer small businesses and take fewer risks with capital," says Tannebaum. All of that hurts economics growth.

Tannebaum is concerned not only that Trump will cut immigration in the future, but that Trump’s anti-immigrant rhetoric and controversial travel ban is already encouraging the best young minds in the world to look elsewhere for their college educations and early careers.

"If smart kids get educated elsewhere, the U.S. will experience a talent drain that we will certainly come to regret," he warns.